Flow Injection Analysis of Nitrite Nitrogen in Seawater Introducing Standard Addition Method

A flow injection analysis of nitrite nitrogen (N-NO2-) in the samples which contain relatively high degrees of salt is described. The N-NO2- was optically detected by use of Griess method. Five pseudo-seawater samples containing 40 μg L-1 N-NO2- with 0, 1, 2, 3, or 4% sodium chloride (NaCl) were tested using two quantitative analysis approaches. In an absolute calibration method, approximately 30% of positive errors were found in the presence of NaCl. On the other hand, the errors fell within the range of −2.6 to +7.3% by introducing a standard addition method. The latter method has successfully been applied to the determination of nitrite nitrogen in real seawater and estuary water

Erythroblastosis of the Donor Twin of Twin Anemia-Polycythemia Sequence

Twin anemia-polycythemia sequence (TAPS) is a group of disorders in monochorionic twins characterized by a large intertwin hemoglobin difference without amniotic fluid discordance. Reticulocyte count is used to diagnose this condition, but little is known about the role of erythroblasts, which are the prior stage of reticulocytes. In the present case of TAPS, the 25-yr-old Japanese mother showed no signs of oligohydramnios or polyhydramnios throughout gestation. The twins were born at 36 weeks and 6 days, weighing 2,648g and 1,994g. The intertwin hemoglobin difference in umbilical cord blood was (21.1－5.0＝) 16.1g/dL and the donor twin showed signs of chronic anemia, including myocardial hypertrophy and pericardial effusion. Erythroblastosis of the donor twin was prolonged (53,088.5, 42,114.8 and 44,217.9/μL on days 0, 1 and 2, respectively). Erythroblastosis, which indicates chronic anemia, is also a good diagnostic indicator of TAPS

Case-based similar image retrieval for weakly annotated large histopathological images of malignant lymphoma using deep metric learning

In the present study, we propose a novel case-based similar image retrieval (SIR) method for hematoxylin and eosin (H&E)-stained histopathological images of malignant lymphoma. When a whole slide image (WSI) is used as an input query, it is desirable to be able to retrieve similar cases by focusing on image patches in pathologically important regions such as tumor cells. To address this problem, we employ attention-based multiple instance learning, which enables us to focus on tumor-specific regions when the similarity between cases is computed. Moreover, we employ contrastive distance metric learning to incorporate immunohistochemical (IHC) staining patterns as useful supervised information for defining appropriate similarity between heterogeneous malignant lymphoma cases. In the experiment with 249 malignant lymphoma patients, we confirmed that the proposed method exhibited higher evaluation measures than the baseline case-based SIR methods. Furthermore, the subjective evaluation by pathologists revealed that our similarity measure using IHC staining patterns is appropriate for representing the similarity of H&E-stained tissue images for malignant lymphoma

Feedback standard addition method coupled flow injection analysis : Validation by spectrophotometric determination of nitrite in seawater

The standard addition method is a powerful tool to eliminate matrix interferences and enables accurate determinations, but it is time-consuming and labor-intensive. This paper proposes a feedback standard addition method coupled flow injection analysis, FB-SAM/FIA, for the rapid and accurate determination of trace interest in seawater samples. This approach automatically prepares spiked samples by feeding back the peak height in the fiagram, thus significantly improving the sample throughput compared to the manual standard addition method. Spectrophotometric determination of NO2- with the Griess assay was used as an evaluation model. The proposed technique demonstrated a sample throughput of 3 samples/h, ranging from 0.0050 mg L-1 (LOD) to 0.125 mg L-1 NO2-. The accuracies of NO2- determination with FB-SAM/FIA and an absolute calibration method were tested using natural seawater and pseudo-seawater samples containing 0.040 mg L-1 NO2- in 0, 1, 2, 3, and 4% sodium chloride media. With the absolute calibration method, the calculated concentration increased with an increase in salinity, reaching an overestimation of about 40%. On the other hand, FB-SAM/FIA suppressed the errors in the range of -7.8% to 1.3% and applied successfully to the determination of NO2- in the natural seawater samples